1. Field of the Invention
This invention relates to organic materials which are particularly useful in preparing polymers which are useful in the graphic arts. In one of its aspects, this invention relates to the use of such materials to prepare crosslinkable polymers which can be incorporated into radiation-sensitive elements to obtain a desirable combination or properties.
2. Description of the Prior Art
Conventional vinyldiaryl ether monomers and polymers formed therefrom are disclosed in U.S. Pat. No. 2,522,501, issued Sept. 19, 1950. The monomers are generally prepared by reacting a diaryl ether with acetyl chloride, forming a carbinol by reduction and dehydrating the resulting carbinol. Polymerization occurs when the monomers are heated in air at high temperatures. The disclosed monomers and the polymers prepared therefrom contain only unsubstituted aryl groups.
U.S. Pat. No. 3,055,947, issued Sept. 25, 1962, discloses vinylaryl ether monomers which are formed from the reaction (at 50.degree. to 200.degree. C.) of a haloalkyl aromatic halomethyl compound ##STR2## with an hydroxyl R.sub.1 OH in the presence of a base metal catalyst, wherein:
Ar is aryl;
R is hydrogen or methyl;
R.sub.1 is hydrogen, alkyl, aryl or aralkyl;
X is a halide;
Z and Z.sub.1 are either hydrogen or halide; and
n is an integer of 1 to 3.
R.sub.1 can also be a substituted aryl radical. This reference is typical of the art which shows the preparation of vinylaryl ether monomers by a reaction of a halogenated alkylbenzene with a phenol in a basic environment. One of ordinary skill in the art would not expect the disclosed method to be useful in the preparation of aldehyde-containing polymers because it is expected that the aldehyde would react with another aldehyde group or with the vinyl moiety thereby causing crosslinking.
It is desirable, however, to form vinylaryl ether monomers which have aldehyde substituents. Polymers formed from such monomers would provide crosslinking sites for further reaction with various reagents, such as amines and the like. In the reaction environment taught by U.S. Pat. No. 3,055,947, it is expected that any aldehyde-containing monomers would prematurely gel because of spontaneous crosslinking or polymerization. Furthermore, Ringsdorf et al, Macromolecular Chem., 31, pages 27 through 49 (1959), disclose that vinyl compounds containing aldehyde groups polymerize to form insoluble polymers. One would expect a monomer containing an aldehyde group to form a crosslinked polymer during any conventional polymerization reaction.
Gibson et al, J. Poly. Sci:Poly. Chem. Ed., 12, pages 2141 through 2143 (1974) and Gibson, Macromolecules, 8, pages 89 and 90 (1975), disclose that homopolymers and copolymers containing recurring units of vinylbenzyl phenylethers can be prepared by reaction of a phenol with a polymer containing recurring units of vinylbenzyl chloride in a basic environment. The phenyl groups can be substituted with a variety of radicals, including aldehydes. Not all copolymers containing aldehyde-substituted aryl ether units can be made by this method, however. In the basic environment of the phenol-poly(vinyl benzyl chloride) reaction, many copolymers containing certain substituents or functional groups hydrolyze or degrade. These substituents are reactive with and susceptible to attack or degradation by a base. By "susceptible to attack or degradation by a base" is meant an ability to undergo a chemical reaction with a base to form a species with a chemical structure different from that of the starting species. This ability includes such severe alterations that the degraded material cannot be restored simply by neutralizing the product species with an acid. Examples of such substituents and monomers containing them are given below in the Detailed Description of the Present Invention. Therefore, one could not make aldehyde-containing copolymers by the method described in the Gibson references.
Hence, a method of producing polymerizable vinylaryl ether monomers containing aldehyde groups, whereby gelation due to spontaneous polymerization and/or crosslinking is not allowed to occur, would be highly desirable. It would be further desirable to have a method of producing uncrosslinked polymers from such vinylaryl ether monomers. Such polymers could also contain recurring units of polymerizable monomers having functional groups which may be susceptible to attack or degradation by a base.